Low power and Lossy Networks (LLNs), e.g., sensor networks, have a myriad of applications, such as Smart Grid and Smart Cities. Various challenges are presented with LLNs, such as lossy links, low bandwidth, battery operation, low memory and/or processing capability, etc. One example routing solution to LLN challenges is a protocol called Routing Protocol for LLNs or “RPL,” which is a distance vector routing protocol that builds a Destination Oriented Directed Acyclic Graph (DODAG, or simply DAG) in addition to a set of features to bound the control traffic, support local (and slow) repair, etc. The RPL architecture provides a flexible method by which each node performs DODAG discovery, construction, and maintenance.
Large scale LLNs are typically divided into smaller more manageable sub-networks or “routing domains” (often called a personal area network or “PAN”, such as when using IEEE 802.15.4 terminology). Devices participate in only one routing domain at a time. Due to the scale and embedded nature of LLNs, devices autonomously join a routing domain and form associated routes to allow the forwarding of traffic. From time to time, LLN devices may choose to switch to a different routing domain, called routing domain migration. For example, one cause of routing domain migration is the loss of connectivity to other devices in the routing domain. Another cause is an attempt to optimize communication performance (e.g., by moving to a routing domain with fewer nodes or attaching to a device that advertises a lower route cost).
After joining a new routing domain, the device must obtain a new address (especially when address prefixes are bound to routing domains), discover new routes, advertise its new address, and notify other services of its new address. As a result, during the migration process, services attempting to send traffic to the migrated device will use the old address and messages will not be properly routed to the device.